This resource provides a detailed chronology of Mary Shelley's life and work, as well as several contemporary reviews of her novels and of a play inspired by Frankenstein.
1. "Mr. Heber" is Richard Heber (1773-1833). The "gentleman of your acquaintance" is John William Ward, Lord Dudley (1781-1833). The article referred to is #81. Devon MS. 1149M (f.79), WG to Copleston, 18 Oct. 1810, makes it clear that Dudley had recently submitted his first contribution. Bodleian MS. Eng. lett. d.309 (f.20), Richard Heber to Edward Copleston, [3 Mar. 1810], says WG thanks Copleston for the article on Sydney Smith's sermons and asks permission for Gifford and Dr. Ireland to make alterations and additions, to give the article pungency.
3. Evidently Colonel Bath in Henry Fielding's Amelia (1757), though Gifford misremembers the speaker and the line. In Book II, chapter 1, Captain Booth states, "Good heavens! Madam ...what a magnanimity of mind did her behaviour demonstrate!"